Various powered floor cleaning machines are known in the art, and they can be divided into the following two categories: in the first case, the operator is standing on the floor and walking behind the machine (“walk-behind” machines), in the second case, the operator is sitting on the machine itself (“ride-on” machines). Both systems have advantages and drawbacks.
Having the advantage of being space-saving and flexible in handling, “walk-behind” machines like the ones disclosed, f.e., in EP 0 788 761 and 1 262 138 have the following drawbacks, though. Firstly, the cleaning speed is limited because the machine has to be moved by the operator, and due to the tiring of the operator, the cleaning speed will be even further reduced during the cleaning process. Furthermore, the operator walks behind the machine and thus has only limited or no view on the working area. As a consequence, the cleaning of edges and a precise steering is difficult—this can be the cause for damages on the machine as well as on the furnishing. Furthermore, the guiding and steering of the whole machine must be performed by handcraft. However, due to the rotating cleaning members, the machine tends to deflect from the desired moving direction which imposes additional problems on the manual steering—EP 0 788 761 addresses this problem. Finally, a backwards approach to walls for picking up cleaning solution and dirt is difficult if not impossible.
“Ride-on” machines like the one disclosed, f.e., in EP 0 951 857 eliminate the above mentioned drawbacks of “walk-behind” machines at the price of other drawbacks. Firstly, in contrast to “walk-behind” machines, “ride-on” machines are very space-consuming because they have to be large enough such that the operator can sit on them on a driver's seat. Furthermore, it is very uncomfortable for the operator to jump on and off the machine to get things out of the way or pick up debris etc. Finally, in distinct areas, the operator has to simultaneously control two directions: the front for driving and the side for cleaning in the vicinity of edges.
U.S. Pat. No. 5,507,138 describes a lawn mowing machine where the operator is standing on the machine on a platform which is located between the rear wheels. However, due to the fact that this machine is not directed at cleaning a floor but cutting lawn and is, thus, used on rough ground which can also include steep hills, the platform is located as close to the ground as possible. Furthermore, the machine is equipped with wheels profiled for outdoor use as well as a heavy combustion engine for the cutter which can deal with these rough outdoor conditions. Each of the rear wheels is driven by a hydrostatic motor which is in communication with a hydrostatic pump. In operation, when the cutter engine is running, hydraulic fluid is delivered to each of the wheel motors, wherein the driving direction of the motors depends on the fluid direction, i.e., on the fluid path through corresponding conduits. In this way, the operator can cause the rear drive wheels to either both be driven in the forward/rearward direction or one be driven in the forward direction with the other being driven in the rearward direction. However, due to the above mentioned construction of the hydrostatic motors, the operator has to pre-select the moving direction of each motor—this results in a considerable rumbling when changing the driving direction of a motor. Thus, this kind of drive is not suitable for indoor use, and in particular not for cleaning purposes. In general there are no considerations regarding light weight and high mobility on a flat ground.